Answer is: ph value is 3.56.
Chemical reaction 1: H₂CO₃(aq) ⇄ HCO₃⁻(aq) + H⁺(aq); Ka₁ = 4,3·10⁻⁷.
Chemical reaction 2: HCO₃⁻(aq) ⇄ CO₃²⁻(aq) + H⁺(aq); Ka₂ = 5,6·10⁻¹¹.
c(H₂CO₃) = 0,18 M.
[HCO₃⁻] = [H⁺<span>] = x.
</span>[H₂CO₃] = 0,18 M - x.
Ka₁ = [HCO₃⁻] · [H⁺] / [H₂CO₃].
4,3·10⁻⁷ = x² / (0,18 M -x).
Solve quadratic equation: x = [H⁺] =0,000293 M.
pH = -log[H⁺] = -log(0,000293 M).
pH = 3,56; second Ka do not contributes pH value a lot.
Since there are 63.01284 grams to one mole of HNO3, then 12.5 moles would be in 450 grams of it.
Labels for a hazardous chemical must contain:
• Name, Address and Telephone Number
• Product Identifier
• Signal Word
• Hazard Statement(s)
• Precautionary Statement(s)
• Pictogram(s)
So the answer is product identifier.
NaBr + CaF2 → NaF + CaBr2 What coefficients are needed to balance the chemical equation? A) 1,1,1,1 B) 1,2,1,2 C) 1,2,2,1 D) 2,1
elena-s [515]
D.
2NaBr + CaF2 --> 2NaF + CaBr2 gives you:
2Na 2Na
2Br 2F
1Ca 1Ca
2F 2Br
This is balanced.
Answer:
Water (H20)
Explanation:
When an acid combine with a base, the reaction is called neutralization and it produces salt and water. This can be seen from the reaction between HCl and NaOH as shown below:
HCl + NaOH —> NaCl + H2O
From the above equation, we see clearly that salt (NaCl) and water (H2O) are the new products form.
